Several types of containers are in general use for the storage of tools. One of these is the usual tool box, which is a closeable structure with a hinged lid, usually provided with drawers and trays of various sizes. Both the drawers and the trays are commonly provided with a vertical-plane separating panels to establish compartments for tools and equipment of various sizes. Another type of container is commonly referred to as a "tool caddy", which is usually a case providing an open rack for the storage of tools in a readily-available position, rather than in a random assortment laid flat in a drawer or tray. The tool caddy will present the tools in an instantly-recognizable array, usually in a vertical position from which the tools can be withdrawn as needed. To provide this feature, the tool caddy usually has horizontal panels provided with openings adapted to receive particular tools, usually in related groups. The problem here is that the needs of each mechanic reflect his own particular type of work and work procedures, and it is difficult, if not impossible, to design one tool caddy that will exactly suit the needs of more than one user. These containers are usually adapted to be either placed on a bench top, hung on a wall, or carried by hand to the job site. Particularly in the latter case, it is extremely important that the unit be adapted to the needs of the particular user.